Where is my 2G? - BUG in Ubuntu?

[Thomas Sprinkmeier]

On Tue, 2007-04-10 at 11:15 +0930, Brian Astill wrote:
> That 2G I "lost" is still lost :-(
> Worse, when I login Dapper insists I have no home directory!
> 
> /etc/fstab says:
> # <file system> <mount point>   <type>  <options>       <dump>  <pass>
> proc            /proc           proc    defaults        0       0
> /dev/hda2       /               ext3    defaults,errors=remount-ro 0       1
> /dev/hdb7       /home           ext3    defaults        0       1
> /dev/hda5       none            swap    sw              0       0
> /dev/hdc        /media/cdrom0   udf,iso9660 ro,user,noauto  0       0
> /dev/hdd        /media/cdrom1   udf,iso9660 ro,user,noauto  0       0
> /dev/fd0        /media/floppy0  auto    rw,user,noauto  0       0
> 
> So, what the fsck?  What have I done wrong, or what have I forgotten?

run
	mount
	mount -a
	mount
mount -a means "mount all the stuff in /etc/fstab" and it's supposed to
be run during boot.
Running it manually might tell you what the problem is.

> As a temporary fix I copied the dot files from hdb7 to hda2/home.  

dot files?

> Not only does this "work", but Ubuntu then recognises home on hda7!
> But, as you can see below, the overall effect is that I have moved 3.9G
>  of files away from hda2 for a net gain of 200M!  :-)
> 
> root at hoarykde:/ # df
> Filesystem           1K-blocks Used Available Use% Mounted on
> /dev/hda2             11661852   9028288   2041168  82% /
> varrun                  387788       144    387644   1% /var/run
> varlock                 387788         4    387784   1% /var/lock
> udev                    387788       152    387636   1% /dev
> devshm                  387788         0    387788   0% /dev/shm
> lrm                     387788     18856    368932   5% /lib/modules/2.6.15-28-386/volatile
> /dev/hdb7             11258648   3903072   6783664  37% /home  
> 
> I found kcore - 804.8M - in /proc with all the zero-length files 
> and directories.  Could this be part of the problem? 

run
	lsof | grep deleted
If you delete a file that's open the file hangs around until it's
closed. Something might be hanging on to a few large files in /home.
lsof will find such files.

/proc is a virtual filesystem. It does not contain actual files and
folders, just kernel information exported in a friendly way.

Do NOT mess with /proc/kcore, it's a file representing your RAM!

> How can I restore my system to health and have the 5G free
>  on hda2 I should have?

run
	tune2fs -l /dev/hdb7
and look for "Reserved block count". By default ext3 reserves 5% of your
disk for root. This might be where you missing diskspace is.

Also, disk GB = 1e9 bytes
df GB = 1024 ** 3 bytes
so you 'loose' about 7% of your disk that way.


Thomas